Vacuum cleaners are widely used for picking up dirt and debris. A vacuum cleaner therefore includes a motor and impeller that together generate a vacuum airflow. A powered brushroll is rotated by a motor and functions to dislodge dirt and debris on an underlying surface. The powered brushroll additionally propels the dirt and debris into the vacuum airflow.
A carpet cleaner machine is a specialized vacuum cleaner. Cleaning a carpet presents extra challenges to a vacuum cleaner. Foreign matter can get down into the carpet fibers, and therefore can be very difficult to dislodge and remove. Furthermore, the foreign matter can comprise dirt and debris that is tangled or embedded in the carpet fibers, that is sticky or capable of hardening or congealing, etc. Consequently, the foreign matter cannot be simply lifted out of the carpet by a vacuum airflow. Such foreign matter usually necessitates the use of a carpet cleaner machine. A typical carpet cleaner machine uses a cleaning liquid to soften and remove foreign matter from carpet fibers. The cleaning liquid can comprise water and/or soaps, detergents, etc. In addition, the cleaning liquid can be heated in order to improve the cleaning action, such as a carpet cleaner machine using steam or steam including a soap or detergent.
A carpet cleaner machine operates by spraying the cleaning liquid down into the carpet and then pulling the cleaning liquid back out of the carpet. The foreign matter is loosened or at least partially dissolved by the cleaning liquid, and therefore is picked up with the cleaning liquid by the vacuum airflow of the carpet cleaner machine. The carpet cleaner machine can additionally employ a powered brushroll or beater bar that works the cleaning liquid down into the carpet and aid in breaking up and removing the foreign matter.
The cleaning liquid contains dirt and debris picked up from the carpet. The cleaning liquid is typically processed by the carpet cleaner machine after it has been picked up in order to separate the cleaning liquid out of the vacuum airflow. The separated liquid can be re-used or can be disposed of by the operator of the carpet cleaner machine. The separated cleaning liquid therefore can be reclaimed and returned to a cleaning liquid tank, or can be kept in a separate “dirty fluid” tank.
In the prior art, the cleaning liquid is typically removed from the vacuum airflow by gravity. The air/liquid airflow is passed into a separation chamber, where the liquid falls out of the airflow and falls to the bottom of a reclamation tank. However, there is a drawback to this prior art approach. The reliance on gravity to pull the cleaning liquid out of the airflow will generally remove the largest drops of liquid. However, suspended liquid in the form of small droplets and/or water vapor is not efficiently removed from the airflow. In addition, the efficacy of this prior art approach depends to some degree on the length of the airflow path, and a prior art carpet cleaner machine therefore can include a serpentine airflow path in order to increase the length of the airflow path. This necessitates a relatively large reclamation area/reclamation tank, increasing the size, weight, and bulk of the prior art carpet cleaner machine. Even with a large reclamation tank, practical considerations of carpet cleaner machine size will limit the size of the reclamation tank.
Another prior art approach is to run the air/liquid airflow through some manner of filter in order to remove the cleaning liquid. The fluid is generally trapped in the filter, and then drops into the reclamation tank. However, this prior art approach also has drawbacks. The filter can clog with liquid and dirt over time, impeding both removal of the cleaning liquid and dirt and impeding the overall cleaning effectiveness of the carpet cleaner machine by reducing the vacuum airflow.